The present invention relates generally to high pressure fluid delivery systems, and more particularly provides a high pressure spray cleaning system having significantly improved sealing and venting means.
Various high pressure fluid delivery systems have heretofore been utilized to convert a flow of high pressure fluid (such as water at 6,000-10,000 psi or more), via nozzle means, to a high pressure spray used to clean a variety of objects. Systems of this general type are exemplified in U.S. Pat. Nos. 3,831,845; 3,834,621; 3,977,603; 3,986,523; and 4,128,207. Such systems typically comprise a hollow body into which the high pressure fluid is forced, and a hollow outlet member communicating with the interior of the body and operatively carrying at least one spray nozzle. A significant limitation of this type of high pressure fluid system is that because the fluid exerts a very high pressure on the interior of the body, the body must be of very strong, and therefore relatively heavy construction. Particularly in the case of large fluid delivery systems, this necessity can significantly increase the overall weight of the system.
Additionally, it is often desirable to provide for driven rotation of the nozzle support member relative to the body to clean interior surfaces or simply to expand the effective nozzle spray area. In the fluid delivery system disclosed in U.S. Pat. No. 3,987,963, this result is achieved by connecting the rotationally driven nozzle support member to a hollow fluid delivery shaft which is rotatably supported within the hollow body and has an inlet end rotatably sealed to the interior surface of the body. High pressure fluid is forced into the inlet end of the shaft, through the shaft interior, and outwardly through the hollow nozzle support member and a spray nozzle carried on the outer end of the support member for rotation therewith.
This construction is intended to isolate the fluid from the interior surface of the body which is intended merely to rotatably support the shaft portion disposed therein. During normal operation of the system, the body is indeed isolated from the high pressure of the supply fluid traversing the shaft. However, upon failure of the shaft seal, high pressure fluid can leak past the seal, along the shaft inlet portion and into the hollow body, thereby at least temporarily exposing the body's interior to essentially the full pressure of the supply fluid. Additionally, the positioning of the shaft-body seal renders it relatively inaccessible, and therefore fairly difficult to periodically inspect and replace.
Accordingly, it is an object of the present invention to provide an improved high pressure fluid delivery system of the general type described, which eliminates or substantially minimizes above-mentioned and other limitations and disadvantages associated with conventional systems.